Temperature dependence of aerobic respiration in a coastal sediment

Abstract The direct temperature dependence of aerobic respiration was determined in sediment from Aarhus Bay, Denmark, in incubations shorter than 12 h at temperature intervals of 1.7°C. Oxygen consumption showed a bimodal distribution between −2 and 80°C indicating the presence of distinct non-thermophilic and thermophilic populations. The thermophilic oxygen consumption had minimum, optimum, and maximum temperatures of 40, 55, and 65°C, respectively, and accelerated strongly after a lag phase of 2–3 h, which may be due to an activation of spores. The source of this dormant thermophilic population is unknown. Oxygen consumption by the non-thermophilic population had minimum and maximum temperatures of